Disertacijoje nagrinėjami kai kurie kategorinių požymių statistinės analizės uždaviniai – ryšių struktūros bei modelio parinkimo ir jo parametrų įvertinimo uždaviniai. Disertacijos tikslas – pasiūlyti ryšių struktūros tarp kategorinių požymių įvertinimo metodą tuo atveju, kai turime didelės dimensijos duomenų rinkinius ir išsklaidytas dažnių lenteles, t. y. kai daugumoje dažnių lentelės ląstelių yra mažas stebinių skaičius arba jos yra tuščios. Ši situacija iliustruojama DNR genetinių sekų statistine analize. Disertaciją sudaro įvadas, trys pagrindiniai skyriai, išvados, naudotos literatūros ir autoriaus publikacijų sąrašai. Įvadiniame skyriuje pristatoma tiriamoji problema ir jos aktualumas, aprašomas tyrimų objektas, formuluojamas darbo tikslas ir uždaviniai, aptariamas darbo mokslinis naujumas bei ginamieji teiginiai. Įvado pabaigoje pateikiami autoriaus pranešimai konferencijose disertacijos tema. Pirmame skyriuje pateikta kategorinių požymių statistinėje analizėje taikomų matematinių modelių apžvalga, šių modelių ryšys su Markovo laukų teorija ir Gibso skirstiniu. Antrame skyriuje atlikta statistinė analizė kai kurioms realioms DNR sekoms Markovo eilės jose įvertinimui bei pirminių ir antrinių DNR grandinių vijų palyginimui: pasiūlyta kategorinių duomenų statistinės analizės metodika, pagrįsta specialia stebimų duomenų forma, apibendrintu logit modeliu bei savirankos testais. Trečiame skyriuje išsklaidytų dažnių lentelės problemai spręsti pasiūlytas semiparametrinis... [toliau žr. visą tekstą] / The dissertation considers some problems in the statistical analysis of categorical variables – the dependence structure between categorical variables and the problems of selecting and assessing the models for this structure. The aim of this dissertation is to propose the method to estimate dependence structure between multivariate categorical variables in case of sparse frequency tables and to apply the proposed method in the statistical analysis of genetic sequences. The thesis layout consists of introduction chapter, three main chapters, conclusions, list of authors’s publications and bibliography chapter. The introduction reveals the investigated problem, importance of the thesis and the object of research and describes the purpose and tasks of the dissertation, research methodology, scientific novelty, the practical significance and defended statements. The introduction end in presenting the author’s publications on the subject of the defended dissertation. In the first chapter of the dissertation various models available for describing the nature of the association between categorical variables are introduced and their link with Markov field theory and Gibbs distribution. In the second chapter the basic notions of DNA sequences and a special structure of genetic data is introduced. The logit models and Markov field theory are applied to assess the dependence structure (interactions) between DNA nucleotides and to test hypothesis about Markov order of these dependencies... [to full text]

The dissertation considers some problems in the statistical analysis of categorical variables – the dependence structure between categorical variables and the problems of selecting and assessing the models for this structure. The aim of this dissertation is to propose the method to estimate dependence structure between multivariate categorical variables in case of sparse frequency tables and to apply the proposed method in the statistical analysis of genetic sequences. The thesis layout consists of introduction chapter, three main chapters, conclusions, list of authors’s publications and bibliography chapter. The introduction reveals the investigated problem, importance of the thesis and the object of research and describes the purpose and tasks of the dissertation, research methodology, scientific novelty, the practical significance and defended statements. The introduction end in presenting the author’s publications on the subject of the defended dissertation. In the first chapter of the dissertation various models available for describing the nature of the association between categorical variables are introduced and their link with Markov field theory and Gibbs distribution. In the second chapter the basic notions of DNA sequences and a special structure of genetic data is introduced. The logit models and Markov field theory are applied to assess the dependence structure (interactions) between DNA nucleotides and to test hypothesis about Markov order of these dependencies... [to full text] / Disertacijoje nagrinėjami kai kurie kategorinių požymių statistinės analizės uždaviniai – ryšių struktūros bei modelio parinkimo ir jo parametrų įvertinimo uždaviniai. Disertacijos tikslas – pasiūlyti ryšių struktūros tarp kategorinių požymių įvertinimo metodą tuo atveju, kai turime didelės dimensijos duomenų rinkinius ir išsklaidytas dažnių lenteles, t. y. kai daugumoje dažnių lentelės ląstelių yra mažas stebinių skaičius arba jos yra tuščios. Ši situacija iliustruojama DNR genetinių sekų statistine analize. Disertaciją sudaro įvadas, trys pagrindiniai skyriai, išvados, naudotos literatūros ir autoriaus publikacijų sąrašai. Įvadiniame skyriuje pristatoma tiriamoji problema ir jos aktualumas, aprašomas tyrimų objektas, formuluojamas darbo tikslas ir uždaviniai, aptariamas darbo mokslinis naujumas bei ginamieji teiginiai. Įvado pabaigoje pateikiami autoriaus pranešimai konferencijose disertacijos tema. Pirmame skyriuje pateikta kategorinių požymių statistinėje analizėje taikomų matematinių modelių apžvalga, šių modelių ryšys su Markovo laukų teorija ir Gibso skirstiniu. Antrame skyriuje atlikta statistinė analizė kai kurioms realioms DNR sekoms Markovo eilės jose įvertinimui bei pirminių ir antrinių DNR grandinių vijų palyginimui: pasiūlyta kategorinių duomenų statistinės analizės metodika, pagrįsta specialia stebimų duomenų forma, apibendrintu logit modeliu bei savirankos testais. Trečiame skyriuje išsklaidytų dažnių lentelės problemai spręsti pasiūlytas semiparametrinis... [toliau žr. visą tekstą]

The problem in this thesis was originally motivated by problems presented with documents of Early England Data Set (DEEDS). The central problem with these medieval documents is the lack of methods to assign accurate dates to those documents which bear no date. With the problems of the DEEDS documents in mind, we present two methods to impute missing features of texts. In the first method, we suggest a new class of metrics for measuring distances between texts. We then show how to combine the distances between the texts using statistical smoothing. This method can be adapted to settings where the features of the texts are ordered or unordered categoricals (as in the case of, for example, authorship assignment problems). In the second method, we estimate the probability of occurrences of words in texts using nonparametric regression techniques of local polynomial fitting with kernel weight to generalized linear models. We combine the estimated probability of occurrences of words of a text to estimate the probability of occurrence of a text as a function of its feature -- the feature in this case being the date in which the text is written. The application and results of our methods to the DEEDS documents are presented.

This thesis considers a communication system with chaotic modulation. Noise-like signals are generated by chaotic systems with different parameters to modulate binary digital signals. Demodulation is performed by both the Extended Kalman Filter (EKF) and Optimum Decoding Based Smoothing Algorithm (ODSA). Simulations are performed using both of these algorithms for different parameters affecting the performance of the communication system. Simulation results of these algorithms are compared.

目前我國地價制度，主要係依地價調查估計規則規定，查估公告土地現值及公告地價。價格評估主要採區段地價方式，可能造成忽略土地個別因素影響，造成評估價格明顯遠離市價。近年來我國推行地價基準地制度，期透過引進不動產估價技術規則之規範，以個別估價方式評估基準地價格，以真實反映價格與市場波動情形。然基準地評價屬一序列式之估價方式，其評估過程是否為獨立且客觀仍須進一步加以驗證。本文依循Quan-Quigley部分調整模型之理念，對高雄市地價基準地之重估價案例進行研究，透過迴歸分析分別衡量估值與當期市場價格、前期估值之關係，推估地價人員之信心水準，並進一步分析地價基準地制度是否能確實反映市場價值波動情形。研究結果顯示估價人員存在價格部分調整策略，信心水準值偏低，存在嚴重依賴前期估值之行為，隱含地價基準地評價存在估價平滑之現象。 / Previous studies defined appraisal smoothing as reduced volatility or the lag structure of appraisal-based index as compared to transaction-based index. Most of these studies examined by aggregate level and used extensive data sets to de-smooth the appraisal-based index. This paper aims to observe smoothing behavior amongst appraisers in Taiwan. It uses re-appraisal data of the land value benchmark in Kaohsiung city and modifies the partial adjustment model, developed by Quan and Quigley. Use the concept of regression analysis to measure the ratio between the current appraisal, current market value and the pre-appraisal. By establish the confidence value, we may observe the behavior of appraisers and public assessors, and distinguish if the behavior is rational or not.

Image processing plays a key role in vision systems. Its function is to extract and enhance pertinent information from raw data. In robotics, processing of real-time data is constrained by limited resources. Thus, it is important to understand and analyse image processing algorithms for accuracy, speed, and quality. The theme of this thesis is an implementation and comparative study of algorithms related to various image processing techniques like edge detection, corner detection and thinning. A re-interpretation of a standard technique, non-maxima suppression for corner detectors was attempted. In addition, a thinning filter, Hall-Guo, was modified to achieve better results. Generally, real time data is corrupted with noise. This thesis also incorporates few smoothing filters that help in noise reduction. Apart from comparing and analysing algorithms for these techniques, an attempt was made to implement correlation-based optic flow

The main aim of the thesis is to define creative accounting and describe selected techniques, which can be encountered in real life, including with their effect on accounting reports. For proper understanding of the issues this thesis also defines accounting in accordance with applicable laws and standards. However, the technique of creative accounting is the result of work of people who are part of an interest group which aims to present the status of the company in a distorted form. For this reason ethics in accounting is also a part of this thesis. The practical part of the work is focused on creative accounting practices and their implications are presented with examples. These examples are accompanied by diagrams presenting the impact of the respective values on selected accounting reports and include explanatory comments.

Submitted by Marlon Pirchiner (marlon.pirchiner.work@gmail.com) on 2014-09-09T12:41:58Z No. of bitstreams: 1 dissertacao_biblioteca.pdf: 20168048 bytes, checksum: 06f8b607a56d91eecc737ff55933780a (MD5) / Approved for entry into archive by Janete de Oliveira Feitosa (janete.feitosa@fgv.br) on 2015-09-09T18:43:32Z (GMT) No. of bitstreams: 1 dissertacao_biblioteca.pdf: 20168048 bytes, checksum: 06f8b607a56d91eecc737ff55933780a (MD5) / Approved for entry into archive by Marcia Bacha (marcia.bacha@fgv.br) on 2015-09-11T12:21:49Z (GMT) No. of bitstreams: 1 dissertacao_biblioteca.pdf: 20168048 bytes, checksum: 06f8b607a56d91eecc737ff55933780a (MD5) / Made available in DSpace on 2015-09-11T12:22:02Z (GMT). No. of bitstreams: 1 dissertacao_biblioteca.pdf: 20168048 bytes, checksum: 06f8b607a56d91eecc737ff55933780a (MD5) Previous issue date: 2014-07-15 / Seismic risk assesment is crucial to make better decisions about engineering structures and loss mitigation. It involves, mainly, the evaluation of seismic hazard. Seismic hazard assesment is the computation of probability which the level of some ground motion intensity measure, in a given site, which, in some time window, will be exceeded. Depending on geological and tectonic complexity, the seismic hazard evaluation becomes more sofisticated. At sites with low seismicity, which is the brazilian case, the relative (geolo- gically) low observation time and the lack of earthquake and tectonic information, increases the uncertainties and makes more difficult the standard analysis, which in general, consider expert opinions, to characterize the seismicity into disjoint zones. This text discusses some smoothing seismicity techniques and their theoretical foundati- ons as alternative methods for seismicity characterization. Next, the methods are exemplified in the brazilian context. / A avaliação de risco sísmico, fundamental para as decisões sobre as estruturas de obras de engenharia e mitigação de perdas, envolve fundamentalmente a análise de ameaça sísmica. Calcular a ameaça sísmica é o mesmo que calcular a probabilidade de que certo nível de determinada medida de intensidade em certo local durante um certo tempo seja excedido. Dependendo da complexidade da atividade geológica essas estimativas podem ser bas- tante sofisticadas. Em locais com baixa sismicidade, como é o caso do Brasil, o pouco tempo (geológico) de observação e a pouca quantidade de informação são fontes de muitas incer- tezas e dificuldade de análise pelos métodos mais clássicos e conhecidos que geralmente consideram, através de opiniões de especialistas, determinadas zonas sísmicas. Serão discutidas algumas técnicas de suavização e seus fundamentos como métodos al- ternativos ao zoneamento, em seguida se exemplifica suas aplicações no caso brasileiro.

[pt] A presente dissertação se insere no contexto da energia eólica, que é a fonte de energia que mais cresce na matriz elétrica brasileira, segundo dados da Empresa de Pesquisa de Energia (EPE), com projeções para que esse crescimento se mantenha. Com isso, a principal motivação do presente trabalho é o fato de que desenvolver e aplicar métodos de previsão cada vez mais precisos para as variáveis determinantes na produção de energia eólica em um aerogerador, como a velocidade do vento, é de crucial importância para o planejamento da operação do sistema elétrico nacional. Logo, o objetivo principal do trabalho é adaptar e aplicar uma metodologia de previsão de séries temporais em um banco de dados formado por medições de velocidade de vento. A metodologia se constrói a partir da análise exploratória dos dados, onde pode se observar características importantes, como estacionariedade na média e uma estrutura sazonal complexa, que envolve um ciclo diário e uma sazonalidade mensal. Com isso, foi adaptado um modelo de amortecimento exponencial com múltiplos ciclos que incorpora simulação de Monte Carlo e decomposição da série através do método TBATS, para realizar as previsões. Como resultados e conclusões, é possível observar que modelo adaptado se mostrou adequado para tratar o problema proposto, quando comparado com os modelos de previsão estabelecidos pela literatura, resultando em um aumento na precisão das previsões realizadas. / [en] This work is in the context of wind energy, which is the energy source that grows more in the Brazilian energy matrix, according to the Energy Research Company (EPE), with projections that this growth will continue. Thus, the main motivation of this work is the fact that developing and implementing increasingly precise forecasting methods for the key variables in the production of wind energy in a wind turbine, such as wind speed, is of crucial importance for planning of the national electric system operation. Therefore, the main objective of this work is to adapt and apply a time series forecasting methodology in a database formed by wind speed measurements. The methodology is built from the exploratory analysis of data, which can be observed important features such as stationary mean and a complex seasonal structure, which involves a daily cycle and monthly seasonality. Thus, it was adapted an exponential smoothing model that incorporates multiple cycles, Monte Carlo simulation and decomposition of the series through the TBATS method, to make forecasts. As results and conclusions, it is possible to observe that model adapted was adequate to address the proposed issue, compared with the forecast models established in the literature, resulting in an increase in the accuracy of forecasts made.

A literatura trata a suavização do lucro líquido como uma das proxies para medir a qualidade da informação contábil (DECHOW; GE; SCHRAND, 2010). Porém, pesquisas sobre suavização do lucro líquido são divergentes em responder se essa suavização aumenta ou diminui a qualidade da informação. Existem trabalhos que testam se o aumento da suavização do lucro líquido aumenta a qualidade da informação por meio da persistência do lucro (TUCKER; ZAROWIN, 2006). Sabe-se, todavia, que os investidores não projetam fluxos de caixa futuros das empresas utilizando somente o lucro líquido, mas as contas de resultado que compõem esse lucro, pois são consideradas relevantes no processo de decisão sobre determinado investimento (BARTON; HANSEN; POWNALL, 2010). Entretanto, desconhecese qual o impacto da suavização sobre as contas de resultado que compõem o lucro líquido. Assim, esta pesquisa procura analisar como o objetivo de suavizar o lucro líquido afeta a persistência das contas de resultado que compõem esse lucro. Nesse sentido, as empresas que fazem parte da amostra foram separadas em empresas que mais e menos suavizam o lucro líquido de acordo com três modelos de suavização encontrados na literatura (LEUZ; NANDA; WYSOCKI , 2003; TUCKER; ZAROWIN, 2006). Posteriormente, foram testadas a persistência das contas de resultado, utilizando o modelo de persistência adaptado de Dechow; Ge e Schrand (2010). Os resultados apontam que as empresas que mais suavizam o lucro líquido possuem contas de resultado mais persistentes em relação às contas das empresas que menos suavizam esse lucro. Além disso, as empresas que mais suavizam o lucro líquido com maior quantidade de accruals discricionários possuem determinadas contas de resultado mais persistentes quando comparadas às empresas que mais suavizam esse lucro com menor quantidade de accruals discricionários. Portanto, os resultados sugerem que o gestor esteja suavizando o lucro artificialmente aumentando a persistência de determinadas contas de resultado, o que caracteriza estas persistências como artificiais. Assim, o investidor que projetar fluxos de caixa de empresas que mais suavizam o lucro líquido com maior quantidade de accruals discricionários poderá ter sua decisão prejudicada / The literature treats the income smoothing as one of the proxies to measure the earnings quality (DECHOW; GE; SCHRAND, 2010). However, research on the income smoothing diverges in whether this smoothing increases or decreases the earnings quality. There are studies that test whether the increase in income smoothing increases the quality of information through the earnings persistence (TUCKER; ZAROWIN, 2006). It is known, however, that investors do not project future cash flows of companies using only net income, but the profit and loss accounts that make up this profit since they are considered relevant in the decision process on an investment (BARTON; HANSEN; POWNALL, 2010). However, the impact of income smoothing on the income statements that make up net income is not known. Thus, this research seeks to analyze how the objective of smoothing the net profit affects the persistence of the income accounts that compose this profit. In this sense, the companies that are part of the sample were separated into companies that more and less smooth the net profit according to three models of income smoothing found in the literature (LEUZ; NANDA; WYSOCKI , 2003; TUCKER; ZAROWIN, 2006). Subsequently, the persistence of the profit and loss accounts was tested using the persistence model adapted from Dechow; Ge and Schrand (2010). The results show that the companies that smoothed the net profit have more persistent profit and loss accounts in relation to the accounts of the companies that least smooth their profit. In addition, companies that the most smoothed their net income with greater amount of discretionary accruals have more persistent profit and loss accounts when compared to the companies that most smooth their profit with less amount of discretionary accruals. Therefore, the results suggest that it is possible for the manager being artificially smoothing the profit, making certain profit and loss accounts more persistent, which characterizes persistence as artificial. Thus, the investor who projects future cash flow from companies that the most smooth the net income with greater discretionary accruals may have their decision impaired, since the projection of future cash flow may not represent the expected future financial performance of the company